ok i was driving my 92 camaro rs when it made a loud pop and quit.. i put a new fuel pump on and it would run for 3 seconds then die.. also put a new distributer, timing chain , while it was not running, so i checked the fuel pressure and it was a few pounds off so put another fuel pump on and it runs now but it is crackin and popping.. thought maybe put a plug wire on the wrong plug but that wasnt it so cleanied the injectors and that wasnt it... what would cause that cracking and popping??